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J. H. SHAW.

DOOR CHECK. APPLICATION FILED JAN.28. 1918. 1,3 1 1, 184. A Patented July 29, 1919.

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INVENTOR 53 9644 E w g Mu-flu TTORNEY J. H. SHAW. DOOR CHECK. 7 APPLICATION FILED JAN. 28. 918. 1,31 1,184. Patented July 29, 1919.

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INVENTOR JZ W emM r ATTORNEY ii ran s rarns PA.

ENT' OFFICE.

JOHN H. SHAW, OF NEW I- IAVEN,.C ONNECTICUT, ASSIGNOR TO SARGENT &, COMPANY, OF NEW I-IAVEN, CONNECTICUT, A CORPORATION OF CONNECTICUT.

DOOR-CHECK.

Specification of Letters Patent. Patented July 29, 1919.

Application filed January 28. 1918. Serial No. 214,135.

To all whom it may concern:

Be it known that 1, JOHN H. SHAW, of the city and county of New Haven and State of Connecticut, have invented certain new and useful Improvements in Door- Ohecks, of which the following is a full, clear, and exact description.

This invention relates to door checks, and more particularly to liquiddoorchecks havingdoor closing springs. V

One of the primary objects of theinvention is to provide improved means for regulating the rapidity of movement of the. plunger or piston during-the closing'movement of the door, at a plurality. of different points. More especially, it is intended to provide a, door check wherein the initial movement of the plungerduring .the closing; of the door canbe accelerated to a variable degree by regulating means, adjustable from the exterior of the check, and including means for. opening and closing one or more intermediate inlets to a passage through which the'liquid moves from one side of the plunger to the other; 7

The principal object offlthis invention is to improve the liquid door check disclosed in the Patent No. 1,123,810, granted to me Jan. 5,.1915;. In this patent, I have disclosed a liquid door check having a spring operated plunger slidaibly mounted in a chamber, the arrangement being such that liquid is confined between one end of the chamber and the plunger, in order that the movement of the plunger toward this end of the chamber may be checked by the liquid. In order that the movement of the plunger may be properly controlled, this patent discloses means for permitting the liquid to es cape from in front of the plunger in a. desired manner, consisting of a. tube mounted in one end wall of the liquid chamber and extending axially within the chamber through an opening formed in the plunger. The tube is provided with'a plurality of ports, through which the liquid is permitted to escape, and with valves controlling the flow of liquid through these ports. The

ports which are provided to controlthe ini tial closing movement of the plunger are controlled by a valve manually operated from one end of the liquid chamber, andthe port which controls the final movement of the plunger is provided with a valve operated from the opposite end ofthe liquid chamber.

In this invention, I have materially improved the means disclosed in my patent mechanism adapted to be mounted in a by pass or passage positioned to one side ofthe l quid chamber. My improved valve mechanism is provided with ad ustable means operable from one end of the chamber for retarding the plunger movement at any desired point 111 the 1111151211 closing movement of the door, and with independently adjustable means operable from the same end of the chamber for controlling; the passage of the liquid from one side of the plunger" to the other during the last part of the door closing movement, so that, if desired, the last par't'of the doorelosing stroke may be very slow, in order to prevent slamming of the door.

The improved means hereinafter more fully described for controlling the-flow of liquid from. one end of the liquid chamber to the other is very compact, consistsof but few parts, and may be easily manufactured; furthermore, it may be very easily and quickly adjusted to the desired position,

'since the valve which controls the initial movement of the plunger is provided with graduations which indicate the different positions to which the valve should be set to check the closing of the door as desired. By providing the two controls above mentioned, the check isadapted for use on inside doors, doors. opening in' off the street, etc, where it is desirable to :move the dbon quickly outwardly opening entrance doors, where it is desirable to check or retard the door substantially throughout the closing movement; and likewise on doors where the closing movementis resisted by astrong draft, or

otherwise, and where it is desirable to move the door forcibly to closed position during thelast few inches of the closing movement.

To these and other ends, the invention consists in the novel features and combinations of parts to be hereinafter described and claimed.

In the accon'ipanying drawings,

Figure 1 is a plan view of my improved door check shown mounted upon a door, with its cooperating arms shown in the position they assume when the door is closed;

Fig. 2 is an enlarged end view of my door check;

Fig. 3 is a side view of Fig. 2, a portion of the piston chamber being broken away in order to disclose the interior thereof, showing the parts in the position they assume when the door is open;

Fig. 4 is a fragmentary sectional view, taken on line 44 of Fig. 2;

Fig. 5 is a. fragmentary sectional view, taken on line 55 of Fig. 2;

Figs. 6 and 7 are views similar to Fig. 5, but show different ports open to the liquid passage;

Fig. 8 is a more complete sectional view taken on line 55 of Fig. 2 looking down, showing still another port open.

Fig. 9 is a side view of my improved liquid controlling valve removed from the door check;

Fig. 10 is a rear end view of Fig. 9; and

Figs. 11 and 12 are side views of details of the fluid controlling valve.

In the drawings, I have designated my improved door check in its entirety by the numeral 10, and in Fig. 1, I have shown this door check applied to a door, indicated by the heavy line D; the usual arms which cooperate with the door check are designated as 11 and 12, and are shown in the position they assume when the door is closed.

The door check 10 has a horizontally disposed piston chamber 13, and a vertically disposed spindle chamber 14. The door check is further provided with flanges 15, having screw holes 16 formed therein by means of which the door check may be secured to a door or door frame, as may be desired.

The chambers 13 and 14 are separated by a wall 17, having a threaded opening 18 formed therein which is positioned centrally of the chamber 14. The upper end of the chamber 14 is provided with a cap or cover 19 having an pening formed centrally thereof. Rotatably mounted in the opening 18 and in the opening formed in the cap 19 is a spindle 20 having formed upon the inner end thereof a cam 21. A stuffing box is preferably mounted in the threaded opening 18 in which the spindle 20 is rotatably mounted, the stufling box being provided in rder to prevent the fluid from passing from the chamber 13 to the chamber 14. In the chamber 14 is mounted a coiled spring (not shown), which spring tends to rotate the spindle 20 in one direction, in order to close the door controlled by the door check. The inner end of the spindle 20 is preferably seated in a socket 22 formed in a wall of the chamber 13. One end of the piston chamber 13 is preferably made integral with this chamber and is designated by the numeral 23. The opposite end of the chamber 13 is preferably threaded and is closed by a nut or cap 24. Slidably mounted in the piston chamber 13 is a double 7 headed piston 25, the opposite ends of which are connected by a bridge-like member 26, so that a space is formed between the opposite ends of the piston in which is mounted the cam 21, the arrangement being such that when the spindle 20 is rotated, the piston is moved back or forth in its chamber by the cam 21, which contacts with either one or the other of the heads of the piston 25. The left hand head of the piston, shown in Fig. 3, fits snugly within the chamber 13, so that the liquid confined in this end of the chamber cannot pass between this head of the piston and the walls of the cylinder. It will, therefore, be seen that the piston cannot be moved toward the left hand end of the piston chamber, as shown in Fig.

3, unless some means is provided for permitting the liquid to escape from this end of the chamber in which it is confined. The structure so far described is wellknown and need not be further described in this specification.

As above indicated, the object of my invention is to improve the means for controlling the flow of the liquid from one end of the chamber 13 to the other. I have accomplished this object by providing a. passage 27 which is preferably made by forming an enlarged portion 28 upon the exterior surface of the chamber 13. This portion preferably extends from the left hand end of the piston chamber, as shown in Fig. 5, to substantially the central portion of the chamber, and extends parallel to the axis of this chamber. In this enlarged portion is formed the passage 27 above mentioned, which preferably consists of a drill hole extending from the outer face of this enlarged portion throughout the greater portion thereof, and adjacent the inner end of this enlarged portion 28 is formed a smaller opening 29, the inner end of which communicates with a clearance space formed in the chamber 13 adjacent the threaded opening 18, which clearance space permits the liquid to flow freely about the right hand half of the chamber 13 in which one head of the piston operates.

In the passage 27 is rotatably mounted a 12 tubular valve member 30, which has a number of drill holes formed in the walls thereof, the arrangement of which will be hereinafter described. This valve member 30 extends throughout substantially the entire length of the passage 27, "and has rigidly secured to the outer end thereof a "knurled disk 31, by means of which the valve may be rotated in the passage 27. Astu-ffing box is formed about the valve member 30, consisting of packing '32,, and a cooperating threaded gland nut '38,which stuffing box prevents the liquid from escaping. from the chamber 13 about the outer surface of the valve member. s I I The tubular valvemember 30 is provided with a plunger 3st adjustablymounted therespindle a stuffing box consisting of the packing 37 and a threaded gland nut 38 is provided. This gland nut has a threaded opening formed centrally thereof in which the spindle 35 operates.

In order that the movement of the piston 25 toward the end23 of the piston chamber may be checked at any one of a plurality of positions along its travel, I. provide a 'number of ports which form communication from the interior of the chamber 13 to the passage 27, four being provided in the door check which I have shown as illustrating my invention. These ports I havedesignated as 39, 40, 41 and 4:2. It will .be apparent that if all four of these. ports should be permitted to communicate freely withth'e passage 27, the liquid confined in the left hand end .of the cylinder 13 would esoape "from thi end of the cylinder through each of these four ports into the; chamber 27 'untilthese ports were success1vely closed or covered by the left hand head of "the'piston 25 as this piston moves toward the'end 23 of the cylinder .underthe influence o'fth'e spindle 20 which is operated by the coiled spring, above mentioned. Itwill also be apparent that the movement of the piston .25 just referred to may be retarded as desired by closing any one or 'moreofthese ports. "If it should be desired to permit the .door controlled by this door stop to close freely through only a small angle, and ,then be retarded throughout the rest of the are through which it must movein order to reach the closed position, this maybeaccomplished by closingthe ports 40 and 41 by meansof thetube 30, and by opening the port 42, asshownin Figlli, so that the fluid will pass freely'through the port 42 until this .port is covered byfthe piston head, whereupon the piston will {be retarded throughout the rest of its tjravelfiby the liquid which can then escape from in front "of the same only through the port '39, the

opening through which is controlled by the independently adjustable plunger 34.

Should it bedesired to permit the door upon which my door check is applied to close freely through a greater'angle than the angle just referred to, and then be retarded while moving through the remaining are through WlllCliit must pass 111 order to become closed, the ports 40 and 412 may be closed and the port 41 opened, as in Fig. 7,

so that the "liquid will pass freely through this port until it is closed by the head of the piston 25 passing over the same, and should it be desired to permit the door to swing freelynntil it is nearly closed, and then check it while it moves through the remaining arcthrou'ghwhich it must pass before it becomes closed, "this may be accomplished by closingthe ports 41 and 4:2, and openingthe port-4E0, as'in Fig. 8, so that the liquid may escape freely through this port 10 until it is closed by the piston 25.

In order that the ports maybe opened and closed in the manner above described, I form a number of drill holes in the tube 30 positioned so that one of the drill holes may be brought into alinement with each of the ports 40, 4:1 and 42,'and in addition to these "drill holes I provide additional drill holes which are so positioned that the port 39 maybe opened when any of the other three drill hole 41 which cooperates with the port 41; and in alinement with a third hole 39 I form the drill hole 42 which cooperates w1th the port 42. There is no drill hole .formed in alinement with the last drill hole 39' '(see Fig. 12), as under some conditions it may be desirable to open the port39 without opening any of the other ports. The amountof liquid that is permitted to pass through the drill hole 39 is controlled by the independently adjustable plunger 34 by means of the knurled head 36.

In order to provide means for indicating when the desired port or ports are opened, I

have placed upon the outer face of the disk 31 the numerals 15, 30, 40, and the character C. These reference characters preferably indicate the positions the disk should assume relatively to one corner of the hexagonal portion of the head formed upon the'end 23 of the cylinder, which portion serves as a pointer, as clearlyshown in Fig. 2. I have used the letter C to indicate the position the disk 31 assumes when the ports 40, 41 and 42 are closed, While the numeral 15 indicates the position the disk occupies when it is desired to permit the door to close freely until it forms an angle of substantially 15 with its closed position, before the door is materially retarded. Likewise the numerals 30 and 40 indicate the positions the disk 31 assumes when it is desired to start the checking of the door when it reaches an angle of 30 and 40, respectively, with its door frame.

. From an inspection of Fig. 2 of the drawing it will be seen that one corner of the nut formed upon the head 23 projects over a marginal portion of the disk 31, that is, the marginal portion of this disk rotates in a. saw-cut formed in a corn-er of this nut, as shown in Figs. 1 and 8. In order to permit the disk 31 which is rigidly secured to the tube 30 to be moved to its operative position, a notch 43 is cut in this disk as shown in Fig. 10 to clear the adjacent corner of the nut formed upon the head 23. After the disk 31 has been moved to its operative position, it may then be rotated since the marginal portion of this disk will rotate in the saw cut above mentioned, and in order to form stops which limit the angle through which the disk 31 may be rotated, the screws 44 are provided which contact with opposite faces of the hexagonal portion of the head 23.

I11 Fig. 5 of the drawing, I have shown all three of the ports 40, 41 and 42 closed, and the port 39 partially closed by the plunger 34. This is the position the tube 30 assumes relatively to its port when the letter C upon the disk 31 is turned opposite the pointer above referred to. hen the parts are turned to this position, the piston 25 will be retarded uniformly throughout its entire travel, and will operate exactly the same as it would if the ports 40, 41 and 42 had been omitted from my structure. In Fig. 6 of the drawing, I have shown the port 39 partially closed, as in Fig. 5, and the port 42 is shown to be opened. This is the position the parts assume when the numeral 40 upon the disk 31 is positioned opposite its pointer, in which position the piston 25 will be permitted to move freely in its path of travel until its forward end covers this port. The piston will then be retarded throughout the remaining part of its travel since the liquid can escape in front of the same only through the port 39. In Fig. 7, I have shown the plunger 34 positioned as in Figs. 5 and 6, and have shown the port 41 opened, this being the position the parts assume when the numeral 30 on the disk 31 is positioned opposite its pointer. lVhen the parts assume this position, the piston 25 is permitted to move freely until its forward end covers this port, and in Fig. 8, I have shown the plunger '34 I pass in the opposite direction.

in the same position shown in the other figures, and I have shown the port 40 opened to permit the liquid to pass freely therethrough, this bein the position the parts assume when the numeral 15 upon the disk 31 is positioned opposite the pointer, this position being the one illustrated in Fig. 2 of the drawing. i

Inorder to permit doors provided with liquid door checks to open freely, it is necessary to provide means for permitting the liquid to pass freely from one end of the piston to the other when the door is being opened. This is usually accomplished by forming a hole through the piston and providing a one-way valve in the same, so that the liquid may pass freely in one direction from one side of the piston to the other, which is the direction it must pass in order to allow the doorto open freely, but cannot This particular structure is not illustrated in the drawings, since the same is well-known and is illustrated in my Patent No. 1,123,810, above mentioned. I

From the above description, it will be seen that I have provided simple but efficient means, operable from the exterior of my door check, for permitting the door to close freely until it has reached a desired position, and then to retard the closing of the dooras much at'may be desired throughout the remaining angle through which it must travel in order to reach its closed position, so that a door provided with my improved door check may be made to close properly without banging, under any condition to which the operation of the door may be subjected.

I have not attempted to illustrate or describe the numerous changes which may be made in the details of the construction which may be adopted within the scope of the invention as defined in the claims as various changes in the details of the device may be made without digressing from the scope of my inventive idea.

In wording the annexed claims, it has been thought advisable to take the viewthat the ports 39, 40, 41 and 42 are inlets for permitting the liquid to reach the bypass 27, rather than to view them as outlets for the cylinder 13, these ports 39, 40, 41 and 42 are, therefore, designated in some of the claims as inlets.

lVhat I claim is:

1. In a liquid door check, a checking cylinder, a piston therein, a passage formed in a wall of the cylinder connecting the spaces at opposite sides of the piston, means regulable from the exterior of the check to control the flow of the retarding liquid between said spaces, and other means regulable from the exterior of the check for causing an additional retarding action of the liquid on the piston to commence at any of a plurality of points in the path of the piston; substantially as described.

2. In a liquid door check, a cylinder, a piston therein, a primary controlling means for varying the rate of flow of the retarding liquid from one side of the piston to the other, and a secondary controlling means regulable from the exterior of the check for causing a substantial retarding action to begin at any of a plurality of points in the path of the piston, both of said controlling means being mounted in a Wall of the cylinder; substantially as described.

3. In a liquid door check, a cylinder, a piston therein, a passage extending substantially throughout the length of travel of said piston and connecting the spaces at opposite sides of the piston, means to control thefloW of liquid between said spaces,

and additional means for permitting the liquid to escape from in front of said piston, said last mentioned means controllable manually from the exterior of the check, and automatically closed by the movement of the piston, to cause a substantial increase in the retarding action of the liquidon the piston to commence at any of a plurality of pointsin the path of the piston; substantially as described.

4:. In afluid door check, a cylinder, a piston therein, a passage formed in a. Wall of said cylinder connecting the spaces at opposite sides of the piston, controlling means accessible at the exterior of the cylinder and cooperating. with said passage to throttle the fiovv of fluid through the same, and a second controlling means accessible at the exterior of the cylinder, for opening the intermediate portion of said passage to the interior of the cylinder or closing it off therefrom Without throttling or obstructing the flow of fluid through said passage; substantially as described.

5. In a fluid door check, a cylinder, a piston therein, an adjusting device at one end of the cylinder for varying the rate of flow from one side of the piston to the other throughout the entire movement of said piston, and a second adjusting device at the same end of the cylinder for causing the retarding action to begin at different points in the path of the piston; substantially as described.

6. In a fluid door check, a'cylinder, a piston therein, a passage connecting the spaces at opposite sides of the piston, said passage having a plurality of inlet ports formed therein, device at one end of the cylinder for controlling one'of said inlet ports, and a second device at the same end of the cylinder to control the remaining inlet ports; substantially as described.

7. In a liquid door check, a cylinder, a piston therein, a by-pass formed in a Wall of said cylinder for the passage of liquid from one side of'the piston to the other, and means operable from the exterior of said cylinder to open the intermediate portion of the by-pass to the liquid confined in the cylinder in front of the piston and close it off therefrom, Without throttling the flow of liquid through the by-pass; substantially as described.

8. In a liquid door check, the combination With the checking cylinder, of a plunger or piston mounted to move therein, a by-pass formed in a Wall of said cylinder for permittin'g the passage of liquid from one side to the other of said piston, a seriesof intermediate inlets to said by-pass adapted to be closed in succession by the movement of said piston, and a single means accessible from the outside of said cylinder for closing directly all of said intermediate inlets; substantially as described.

9. In a liquid door check, a cylinder, a piston therein, a passage formed in one Wall of said cylinder connecting the spaces at opposite sides of the piston and having intermediate of its ends a plurality of ports to establish communication between the intermediate portion of said passage and the interior of the cylinder, and a single device cooperating With'sa-id ports directly to control such communication; substantially as described.

10. In a liquid door check, the combination With the checking cylinder, of a plunger or piston mounted to move therein, a by-pass for permitting the passage of liquid from one side to the other ofsaid piston, means for varying the flow of liquid through said b-y-pass during the movement of said piston, and mechanism including inlet ports formed ina Wall of the cylinder for regu lating from the outside of said cylinder the flow. of. liquid through said by-pass and thereby controlling the operation of said piston; substantially as described.

11. In a door check, the combination of a checking cylinder, a plunger movable therein, means positioned to one side of said plunger afiording a passage from one side of theplunger to the other, said passage'having a plurality of intermediate ports adapted to serve as inlets for the liquid during the. initial part of the door closing movements, means associated With said passage for opening and closing said ports, and thereby varying the initial closing movement, and other means associated with said passage to throttle regulably the flow of liquid during the final closing movement so that such final closing movement may be retarded to the desired extent; substantially as described.

12. In a door check, thecombination of a checking cylinder, 2. plunger movable therein, means affording a passage from one side of the plunger to the other, said passage having an inlet adjacent one end of the cylinder through which inlet the fluid passes during the final closing movement of the door, said passage also having an intermediate inlet, means cooperating with said intermediate inlet and ope "able from .the end of the cylinder just mentioned to vary the speed of the initial closing movement, and means cooperating with said first mentioned inlet to retard the final closing movement in order to prevent slamming; substantially as described.

13. In a door check, a fluid chamber, a plunger movable therein, means in a Wall of said chamber affording a passage from one side of the plunger to the other, tubular fluid controlling means rotatable in said passage to vary the initial closing movement of the door, and second means rotatable in said tubular means to retard-the final closing movement of the door to the desired extent; substantially as described.

14. In a door check, a fluid chamber, a plunger movable therein, means affording a passage from one side of the plunger to the other, said passage having a plurality of ports communicating with said chamber, and a valve cooperating with said ports to open any one of said ports to said passage without opening the remaining ports thereto, to vary the initial closing movement of the door, and second means cooperating with said passage to retard the final closing movement of the door to the desired extent; substantially as described.

15. In a door check, a fluid chamber, a plunger movable therein, means affording a passage from one side of the plunger to the other, said passage having a plurality of ports communicating with said chamber, and a hollow valve having a number of openings formed therein positioned to open any one of said ports to said passage Without opening the remaining ports thereto, to

vary the initial closing movement of the door, and adjustable means cooperating with said passage to retard the final closing movement of the door to the desired extent; substantially as described.

16. In a liquid door check, a cylinder, a

piston therein, an adjustable device at one end of said cylinder mounted in a wall thereof and operable from the exterior thereof for varying the rate of flow from one side of the piston to the other, and a second adjustable device surrounding the first device and operable from the same exterior end of the cylinder for causing the retarding action to begin at different points in the path of the piston; substantially as described.

17. In a door check, a fluid chamber, a plunger movable therein, a passage formed in a wall. of said chamber for providing coimnunication from one side of the plunger to the other, said passage having a plurality of ports communicating with said chamber, and a valve controlling said ports whereby any port may be opened to said passage without opening all of said ports thereto, to vary the initial closing movement of the door, and a second adjustable device for retarding the final closing movement of the door to the desired extent; substantially as described.

18. In a door check, a fluid chamber, a plunger movable therein, a passage formed in a wall of said chamber for providing a communication from one side of the plunger to the other, said passage having a plurality of ports communicating with said chamber, and a valve rotatable in said passage having openings cooperating with said ports to open any one of said ports to said passage without opening the other ports, to vary the position at which increased retardation of the plunger will occur, and a second adjustable device for retarding the final closing movement of the door to the desired extent; substantially as described.

19. In a door check, a fluid chamber, a

plunger movable therein, a passage formed in a Wall-of said chamber for providing a communication from one side of the plunger to the other, said passage having a plurality of ports communicating With said chamber, and a valve rotatable in said passage having openings cooperating with said ports to open any one of said ports to saidpassage without opening the otherports, to vary the position at which increased retardation of the plunger will occur; substantially as described.

20. In a fluid door check, a cylinder, a piston therein, a'passage formed in a wall of the cylinder connecting the spaces at opposite sides of the piston, a tubular valve rotatably mounted in said pass-age for cansing the retarding action to begin at different points in the path of the piston, and a second adjustable device mounted in said tubular valve for varying the rate of flow from one side of the piston to the other; substantially as described.

21. In a fluid door check, a cylinder, a piston therein, a passage connecting the spaces at opposite sides of the piston, said passage having a plurality of ports communicating with theinterior of said cylinder and positioned to have their ends closed successively by said piston, means for simultaneously closing all but any one of said ports to cause the retarding action of said piston to begin at different points in its path, and a second adjustable means for retarding'the final closing movement of the door to the desired extent; substantially as described;

'22. In a fluid door check, a cylinder, a

piston therein, a passage. connecting the spaces at opposite sides of the piston, said passage having a plurality of ports com-1 and positioned tobe turned into alinement with the different ports whereby any one of said ports may be opened to. communicate with said passage without opening the remaining ports thereto, to cause the retarding action of said piston to begin at different positions in its path; substantially as described.

2-3. In a fluid door check, a cylinder, a piston therein, a passage connecting the spaces at opposite sides of the piston, said passage having a plurality of ports communicating with the interior of said cylinder, a tubular valve for said ports rotatably mounted in said passage, said valve having openings formed in different walls thereof and positioned to be turned into alinement with the different ports whereby any one of said ports may be opened to communicate with said passage without opening the remaining ports thereto, to cause the retarding action of said piston to begin at different positions in its path, and a second adjustable means for retarding the final closing movement of the door to the desired eX- tent; substantially as described.

24:. In a fluid door check, a cylinder, a piston therein, a passage, a plurality of ports communicating with said passage, a tubular valve rotata'b ly mounted in said passage, said valve having openings formed therein and positioned to be moved into and out of alinement with said ports for causing the retarding action to begin at different points in the path of the piston, said valve having other openings formed therein and positioned in a transverse plane about the same, whereby one of said ports will remain open when the tubular valve is turned to a plurality of different positions; substantially as described.

controlling means; substantially as described.

26. In a fluid door check, a cylinder, a piston therein, a passage formed in a wall of said cylinder connecting the spaces at opposite sides of said piston, a fluid con trolling means within said passage for regulating the flow of the fluid therethrough, said controlling means manually adjustable and constructed to cause the retarding action to begin at any one of a plurality of points in the path of said piston, and graduated means for indication when said controlling means is adjusted to produce a retarding action at a desired point in the travelof the piston; substantially as described.

27. In a fluid door check, a fluid chamber, a plunger movable therein, a passage c011- necting the spaces at opposite sides of the plunger, a fluid controlling means for regulating the flow of the fluid through said passage, comprising a rotatable tube having fluid receiving ports formed in different walls thereof, said controlling means manually adjustable and constructed to begin checking the flow of the fluid at any one of a plurality of points in the path of travel of the piston, and means for indicating the adjustment of said controlling means; sub stantially as described.

28; In a liquid door check, a cylinder, a piston therein, a bypass for the passage of liquid from one side of said piston to the other, said by-pass having a plurality of ports, a tubular valve rotatably mounted in said by-pass having ports formed in different walls thereof, whereby said valve may be turned to open any one of said first mentioned ports without opening the remaining ports, and graduated means cooperate ing with said valve to indicate the port that is opened.

29. In a door check, a fluid chamber, a plunger movable therein, a passage connecting the spaces at opposite sides of the plunger, said passage having a plurality of ports communicating with said chamber, and a manually adjustable valve for controlling said ports, said valve being constructed to open any one of said ports to said passage without opening the remaining ports thereto to cause the retarding action of said fluid to begin at anyone of a plurality of points in the path of travel of the plunger; substantially as described.

30. In a fluid door check, a cylinder, a piston therein, a passage connecting the spaces at opposite sides of said piston, a plurality of ports connect-ing said passage with the interior of said cylinder, a tubular valve rotatably mounted in said passage, said valve having openings formed therein and positioned to be moved into and out of alinement with said ports to open any one of said ports while the other ports are closed, and means cooperating with said tubular valve to indicate which one of said ports is opened.

31. In a fluid door check, a cylinder, a

piston therein, a passage connecting the spaces at opposite sides of said piston, a plurality of ports connecting said passage with the interior of said cylinder, a Valve adjustably mounted in said passage, said valve constructed to open any one of said ports Without opening the remaining ports, whereby the controlling effect of said fluid upon said piston Will begin when the pie ton has reached any one of several positions in its path of travel; substantially as described.

In Witness whereof, I have hereunto set my hand on the25th day of January, 1918.

JOHN 1-1. SHAW.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, I). 0. 

